Walking treadmill



FIG. 1 is a front, bottom perspective view of a walking treadmill, showing our new design;

FIG. 2 is a rear, top perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a left side elevation view thereof; and,

FIG. 8 is a right side elevation view thereof.

The broken lines in the figures illustrate portions of the walking treadmill that form no part of the claimed design. 

CLAIM The ornamental design for a walking treadmill, as shown and described. 